Mold and core blowing machine



Oct. 7, 1969 ET AL 3,470,938

MOLD AND CORE BLOWING MACHINE Filed Sept. 28, 1966 2 Sheets-Sheet l LEON F. MILLER HENRY J. HERBRUGFEN ATTORNkYS INVENTORS Oct. 7, 1969 MlLLER ET AL 3,470,938

MOLD AND CORE BLOWING MACHINE Filed Sept. 28, 1966 2 Sheets-Sheet INVENTORS LEO/V E MILLER HENRY J. HERBRUGGEN B MM g1) ATTORNEY United States Patent 3,470,938 MOLD AND CORE BLOWING MACHINE Leon F. Miller, Rocky River, andHenry J. Herbruggen, Westlake, Ohio, assignors, by :mesne assignments, to The Sherwin-Williams Company, a corporation of Ohio Filed Sept. 28, 1966, Ser. No. 582,696 Int. Cl. B22c 15/24, 15/20 US. Cl. 164-260 16 Claims ABSTRACT OF THE DISCLOSURE A foundry mold or core forming machine which includes a shallow cylindrical sand blow reservoir having sweeping blades or arms therein which are driven to sweep the entire interior surface of the reservoir to facilitate sand turnover.

This invention relates generally as indicated to a mold and core blowing machine and more particularly to an efficient, simplified and economical machine for forming foundry molds and cores.

In conventional foundry mold and core blowing machines, a sand mix is dumped from a hopper into a reservoir or blow chamber which is then pressurized to fiuidize the sand and force the same through blow openings into a pattern containing mold or core box clamped against the reservoir or blow chamber. The air pressure also serves to pack the sand within the box which is provided with vents to form the foundry sand structure. Such machines usually always operate properly initially, but with continued use the sand in the reservoir tends to cake about the blow holes and crater with air passing down through the crater and out the blow holes. Sand also tends to collect in dead spots remaining in the chamber from one blow to the next. The problem of sand not moving through the machine during continued operation leads to frequent down time for cleaning of the blow chamber. This problem is accentuated with the use today of more exotic thermo-setting sand resin mixes which may cause the sand in such dead spots to harden in a relatively short time. It is also noted that hardened sand in a sand reservoir will reduce the capacity of the reservoir and thus affect the ability of the machine to function as desired.

Generally, mold and core blowing machines include vertically elongated reservoirs with funnel blow openings at the bottom thereof. The aforementioned problems of conventional blow machines have made it diflicult to blow sand laterally and obtain uniform sand structure densities and hardnesses. The sand would, of course, normally tend to collect and pack at the bottom of the reservoir and accentuate the problems of cratering, caking, bridging and dead spot hardening.

It is accordingly a principal object of the present invention to provide a foundry mold or core blowing machine which will continually produce molds or cores of uniform density and hardness.

Yet another principal object is the provision of such machine which will not be subject to the down time for cleaning and conditioning ordinarily required.

Yet another important object is the provision of a machine of the type noted which can blow sand molds or cores either downwardly or laterally and which can be converted quickly to and from such blow orientation.

A further object is the provision of a machine of the type noted having a unique blow chamber with no dead spots.

Still another object is the provision of a blow reservoir for a foundry molding machine which will have complete turnover of the sand and which will be of a low 3,470,938 Patented Oct. 7, 1969 clearance simplified construction and economical to maintain.

A yet further object is the provision of a blow reservoir for a foundry molding machine which can be employed in a variety of types of machines to produce a variety of types and sizes of foundry sand products.

Other objects and advantages of the present invention willd become apparent as the following description procee s.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

In said annexed drawings:

FIG. 1 is a side elevation of a machine in accordance with the present invention with the blow reservoir oriented to blow laterally;

FIG. 2 is an end elevation of the machine shown in FIG. 1 taken substantially from line 22 of FIG. 1; and

FIG. 3 is an enlarged vertical section showing the details of the blow reservoir and with such reservoir oriented for blowing vertically.

Referring now to the drawings and more particularly to FIGS. 1 and 2, the illustrated machine comprises a fabricated base 1 having stanchions 2 and 3 aligned on each side thereof. The stanchions 2 and 3 at their upper ends include saddles or slots 4 supporting trunnions 5 and 6 mounted at the opposite ends of transverse block 7.

The block 7 is firmly secured to rods 9 and 10 which are secured at one end to collars 11 of frame 12 and at the opposite end to plate 13. The rods are threaded as indicated at 14 and nuts 15 and 16 are employed to clamp the plate 13 in adjusted position along the rods.

At the top of the frame 12 as seen in FIG. 1 there are additional collars 17 to which are secured rods 18 and 19 threaded as indicated at 20. Nuts 21 and 22 are employed adjustably to clamp the plate 13 therealong. The frame 12 and plate 13 are thus securely adjustably positioned with respect to each other.

The frame 12 supports the base 25 of the clamp pistoncylinder assembly 26, the rod of which supports clamp table 27 of rectangular configuration for movement toward and away from blow plate 28. The clamp pistoncylinder assembly 26 may be pneumatically operated, for example, and may be of the single-acting type with springs 29 and 30 being connected between the table 27 and the frame 12 to obtain return upon the release of pressure within the assembly 26.

In the illustrated embodiment, the table 27 is provided with gibs 32 and 33 supporting mold or core box assembly 34. The assembly 34 may include a flanged box 35 peripherally surrounding pattern 36 supported on pattern plate 37. The box 35 may be provided with peripheral vents and, of course, the pattern and pattern plate may also be vented. The assembly 34 may then be moved normal to the plane of FIG. 1 into and out of proper position.

As seen perhaps more clearly in FIG. 3, the blow plate 28 is releasably clamped by screws 40 to relatively shallow right-circular cylindrical wall 41, one end of which is welded to the plate 13. The screws each include a threaded portion 42 secured to the plate 13 and a clamping head 43 provided with a chordal recess to clear the flange 44 of the blow plate 28 when the screw is rotated. The screws pass through apertures 45 in an annular plate 46 welded to the circular wall 41. The outer end of the wall 41 is provided with a recess in which is seated a sealing member 47. The blow plate is provided with a plurality of blow openings as indicated at 48. The wall 41 forms the peripheral confines of blow chamber 50 which is closed on one side by the blow plate 28 and on the opposite side by plate 51 secured by fasteners 52 through spacers 53 to the plate 13.

Mounted on spacer 55 on the plate 13 is a worm gear reducer 56 driven by motor 57. The output shaft 58 of the reducer 56 is coupled to shaft 59 which extends downwardly through the plate 13 and the plate 51 and recess 60 in below plate 28 is provided therefor. The shaft 59 is journalled at 61 and a seal is provided at 62.

The shaft 59 at its distal end is provided with a transverse blade or plough 64, and at its proximal end with a transverse arm 65 offset 90 from the blade 64. The arm 65 is held in place by collar 66 and the upper edge 67 of the arm is closely adjacent the plate 51. On the outer ends of the arms 65 there are secured by fasteners 68 blades 69 and 70 which extend chordally of the circular wall 41 and the leading edges 71 are closely adjacent the full height of the wall 41 from the blow plate 28 to the wall 41. As indicated in FIG. 2, the leading edge 71 of the blades 69 and 70 may be beveled or sharpened to permit movement closely adjacent the wall 41.

Mounted on the plate 13 is a blow valve 74 which may be of the conventional diaphragm type adapted to admit air at high pressure to the chamber 50 about the clearance between the wall 41 and the plate 51. Also mounted on the plate 13 is a mounting face 75 to which may be secured, alternatively, exhaust valve 76 or fill tube 77. In the embodiment of FIGS. 1 and 2 with the machine in a horizontal or on its side position, the exhaust valve 76 will be secured to the mounting face 75.

At the top of the wall 41 as seen in FIG. 2, there is provided a mounting face 78 to which also either fill tube 77 or exhaust valve 76 may be connected. At the exhaust valve connection, whether it be the mounting plate 75 or the mounting plate 78, a filter may be employed comprised of a plurality of felt disks 79 secured between perforated plates 80 and 81. Such plates may be held together by a clamping bolt 82 and the plate 81 overlies the mounting face 78. In the FIG. 3 embodiment, the exhaust valve may be secured to the threaded opening 83 while the fill tube is connected to the mounting face 75 on the plate 13. In any event the positions of the fill tube and exhaust valve may readily be interchanged.

As seen in FIG. 1, the fill tube 77 includes a butterfly valve 85 with the valve element 86 being operated by a piston-cylinder assembly 87 mounted on bracket 88. The rod of the assembly 87 is connected to the valve element through arm 89. The valve is shown in its opened or partially opened position permitting sand mix to drop from the hopper 90 through the fill section 77 into the blow chamber 50.

Blow plate 28 is secured to a carriage 91 mounted on rollers 92 for movement along plate 93 which extends from the frame 12 through clamping support 94 secured to the wall 41 of the blow chamber. The plate extends beyond the blow chamber and in the embodiment of FIG. 1 overlies a stop rod 95 to support the machine in the horizontal position indicated. Movement of the carriage 91 and the blow plate 28 secured thereto is obtained by piston-cylinder assembly 96 mounted on the underside of the plate 93.

In this manner, when the clamping screws 40 are released, the blow plates 28 can be retracted or lowered to provide access to the interior of the blow chamber 50. In this manner, the blow chamber can quickly be opened and conveniently cleaned out particularly with the aid of the blades 64, 69 and 70. The clamping support 94 for the plate 93 permits the blow chamber supported by the plate 13 to be adjusted by loosening the clamping bolts 97. The precise position of the plate 13 is, of course, obtained by the nuts 15, 16 and 21, 22.

To convert the machine to a vertical operation such as seen in FIG. 3, the blow valve 76 and the fill tube 77 with the hopper thereon are removed and the machine is then swung with the aid of the trunnions 5 and 6. A locking pin may be inserted through the eye 98 on the frame 12 seen in FIG. 1 to hold the machine in a vertical oriented position. The filter assembly is removed and placed in the mounting 78 and the exhaust valve 76 is then attached to the tapped openin'g 83 while the fill tube is mounted on the mounting vface 75.

In operation, the mold or core box assembly 34 will be positioned properly on a table 27 when the table is in its retracted position and the butterfly valve element 86 will be opened to permit sand to drop from the hopper 90 into the blow chamber 50. The drive 57 is energized and through the worm gear reducer 56, the blades 64, 69 and 70 will be continuously turning. The turning blades assist in the complete filling of the chamber 50. The valve element 86 is now closed by means of the piston-cylinder assembly 87 and the clamp piston-cylinder assembly 26 is energized to clamp the assembly 34 against the blow plate 28. With the blades still continuously turning, high pressure air is admitted through the blow valve 74 to cause the sand within the chamber to pass into and be packed within the box 35. At the completion of the blow cycle, the exhaust valve 76 is opened and the table 27 is retracted with the assembly 34 being shuttled from the machine. A new assembly 34 is positioned in place and the valve 86 is again opened to recharge the blow chamber with sand. The assemblies 34 may be shuttled from the machine to curing and stripping stations wherein the assemblies are reconditioned for reuse inthe machine. The blow cycle is repeated as quickly as new mold or core boxes can be placed in the machine and clamped against the blow plate. The blades are, of course, continuously rotating during the operation of the machine.

It can now be seen that the blades 64, 69, 70 and arm 65 will effectively sweep all of the peripheral walls of the chamber 61 and will assist in the distribution of sand entering the chamber from the fill tube 77. In the embodiin such distribution. Moreover, the chordal arrangement of the blades 69 and 70 will effectively scrape or plough the sand away from the peripheral wall 41 while the blades 64 moving adjacent the tops of the blow holes 48 will effectively knife beneath the sand adjacent such blow holes preventing cratering or caking about the blow holes. In this manner, maximum turnover of sand through the blow head is obtained and no sand will be left in dead spots to harden or to reduce the efficiency and capacity of the machine.

Other modes of applying the principles of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We, therefore, particularly point out and distinctly claim as our invention:

1. A foundry sand forming machine comprising a cylindrical chamber, means to fill said chamber with sand, means to blow sand from said chamber into a patterned box and sweeper blade means for continuously sweeping the entire interior surface of said chamber.

2. A machine as set forth in claim 1 wherein said chamber comprises a cylindrical peripheral wall and an annular blow plate closing one end of said peripheral wall.

3. A machine as set forth in claim 2 wherein said sweeper blade means includes rotating blades moving closely adjacent said peripheral wall and said blow plate.

4. A machine as set forth in claim 2 wherein said sweeper blade means includes a diametral blade moving closely adjacent said blow plate offset 90 from diametrically opposed blades moving adjacent the peripheral wall.

5. A machine as set forth in claim 4 wherein said diametrically opposed blades are mounted on a diametral arm moving closely adjacent the wall opposite the blow plate.

6. A machine as set forth in claim 2 including a chamber support plate opposite said blow plate to which said peripheral wall is secured.

7. A machine as set forth in claim 6 wherein said sweeper blade means comprises rotating blades moving closely adjacent said peripheral wall and said blow plate, said blades including a diametral blade moving closely adjacent said blow plate offset 90 from diametrically opposed blades moving adjacent the peripheral wall.

8. A machine as set forth in claim 7 including a shaft axially of said chamber on which said blades are mounted, and drive means for said shaft mounted on said chamber support plate.

9. A machine as set forth in claim 8 including a blow valve and a first mounting face on said chamber support plate, a second mounting face on said peripheral wall, and means selectively to secure to said first and second mounting faces said means to fill said c'hamber with sand or an exhaust valve.

10. A machine as set forth in claim 9 including a trunnion support for said machine for pivoting said machine 90 to orient said blow plate anywhere between vertical or horizontal.

11. A foundry sand blowing machine comprising a cylindrical sand chamber having a flat blow plate closing one end, a support plate for said chamber opposite said blow plate, means operative to clamp -a box against said blow plate, means to pressurize said chamber to blow sand through said blow plate into such box, a relatively shallow cylindrical wall between said blow plate and support plate, a first mounting face on said support plate, a second mounting face on said cylindrical wall, and meansselectively to secure to said first and second mounting faces means to fill said chamber with sand or an exhaust valve.

12. A foundry sand molding machine as set forth in claim 11 including sweeper blade means operative to sweep continuously the entire inner surface of said chamber.

13. A machine as set forth in claim 12 wherein said sweeper blade means comprises rotating blades moving closely adjacent said peripheral wall and said blow plate.

.14. A machine as set forth in claim 13 wherein said blades include a diametral blade moving closely adjacent said blow plate offset from diametrically opposed blades moving adjacent the peripheral wall.

15. A machine as set forth in claim 14 wherein said diametrically opposed blades are mounted on a diametral arm moving closely adjacent the wall opposite the blow plate.

16. A machine as set forth in claim 15 including a shaft axially of said chamber on which said blades are mounted, and drive means for said shaft mounted on said chamber support plate.

References Cited UNITED STATES PATENTS 2,790,215 4/ 1957 Herbruggen 164-201 2,798,266 7/ 1957 Herbruggen 164--22 2,839,798 6/1958 Hinrichs 164-202 2,991,521 7/1961 Bryant et al 164/21 FOREIGN PATENTS 523,261 3/ 6 Canada.

544,268 2/ 1932 Germany.

713,157 11/1941 Germany.

808,319 2/ 1959 Great Britain.

341,426 6/ 1936 Italy.

49,242 3/ 1965 Poland.

J. SPENCER OVERHOLSER, Primary Examiner R. SPENCER ANNEAR, Assistant Examiner US. Cl. X.R. 

